1. Field of Invention
This invention relates to a fluid line coupling for refrigeration refrigerant testing and charging hoses where such coupling is provided with a valve depressor or valve opening element. Such hoses and the couplings are used with testing and charging manifolds for checking both the pressure and vacuum sides of refrigeration systems, and the couplings connect the testing hoses with the testing and charging lines of the refrigeration systems. The refrigeration system fluid or refrigerant lines have externally threaded valve nipples generally with inflation type, such as the so-called Schrader type (such as used in pneumatic tires), end valves. The couplings include, around the valve depressor or valve opening element, internally threaded sleeves for engagement with such nipples. As the internally threaded sleeve threadedly engages the valve nipple, the valve depressor or valve opening element contacts and then depresses the inflation valve stem from its closed position to its open position to allow communication between the manifold and connected system line.
Heretofore, the servicemen, in using the testing and charging hoses, have found that the inflation valve stem does not terminate in such axial position as to make the desired complete contact with the valve depressor when the internally threaded sleeve is in sealed threaded engagement with the valve nipple or terminates in such axial position that it makes contact with and is depressed by the valve depressor or valve opening element before the internally threaded sleeve is in sealed threaded engagement with the valve nipple. In the former instance, no communication between the manifold and connected system line is made; in the latter instance, communication is made too soon and prior to sealing, with the resulting loss of fluid or refrigerant,
2. Description of the Prior Art
Fluid line couplings are many in number.
In U.S. Pat. No. 2,322,462 (June 22, 1943), to Marquardt et al, is disclosed a coupling wherein there is an axially adjustable threaded valve depressor or valve opening element which is first threadedly positioned in its desired axial position and then fixed in such position.
Carlson, in U.S. Pat. No. 2,305,841 (Dec. 22, 1942), discloses a quick-disconnect fluid line coupling having a pair of coaxial body members detachably connected together, one of said members including an enlarged head thereon, a spring actuated valve in the other of said members, a spider and rod combination type valve depressor or valve opening element in said head, said element adapted to unseat said valve upon the uniting of said members, a resilient, for example, rubber, natural or synthetic, element engaging and retaining in position said spider portion of said valve depressor and the resilient member free end terminating in sealing relationship with the other of said members.
Coughlan, in U.S. Pat. No. 2,881,011 (Apr. 7, 1959), discloses a fluid line coupling having a pair of coaxial body members detachably connected, one of said members having a valve depressor and a sealing element and the other one of said members having a spring actuated valve.
In U.S. Pat. No. 3,592,439 (July 13, 1971), to Ritchie, is disclosed a fluid line coupling having a pair of coaxial body members detachably connected with a spring actuated valve in one of said members and an axially adjustable valve depressor or valve opening element in the other of said members. The Ritchie coupling valve depressor is positioned in a resilient sleeve and its body is threaded thereby to enable it to be axially adjustable in that sleeve by rotary turning and twisting movement. Once fixedly positioned in the sleeve, it is incapable of self-adjustment.
In "Simplified Training Course for Refrigerator Servicemen," Second Edition, Revised 1946, Nash-Kelvinator Corporation, 14250 Plymouth Road, Detroit, Michigan, on pages 133 and 137 thereof, is disclosed the concept of an adjusting screw threaded into a resilient sealing gasket in expansion valves used in refrigeration systems.
Jacobsson, in U.S. Pat. No. 2,662,348 (Dec. 15, 1953), discloses the combination of an axially adjustable threaded screw member and a phenolic condensation product sleeve, the latter threadedly engaging the former for rotation and axial movement with respect thereto.
British Pat. No. 572,183 (September 26, 1945), to Regent Autocar Company, Ltd., discloses fluid line couplings where there are valve depressors or valve opening elements having flat parallel opposing sidewalls.
Other prior art fluid couplings are disclosed by U.S. Pat. No. 1,423,873 (Newsom et al, July 25, 1922), U.S. Pat. No. 2,419,642 (Henry, Apr. 29, 1947), U.S. Pat. No. 2,504,569 (Murphy et al, Apr. 18, 1950), U.S. Pat. No. 2,665,928 (Omon et al, Jan. 12, 1954), U.S. Pat. No. 2,931,668 (Baley, Apr. 5, 1960), U.S. Pat. No. 3,448,779 (Horwitt, June 10, 1969) and French Pat. No. 867,500 (Imbrex S.A., Aug. 4, 1941).